Technical Field
The present disclosure relates to a welding apparatus adapted to weld a butted interface or an overlapping part of a workpiece using laser irradiation, and a terminal manufacturing apparatus including the welding apparatus.
Background Art
Wire harnesses are often used for internal wiring of automobiles. A wire harness is a module in which a plurality of coated wires are assembled in accordance with in-vehicle wiring specifications. Terminals for connection (hereinafter referred to as crimp terminals) are crimped to ends of each of the coated wires. When connecting a crimp terminal to a wire end of the wire harness, electrical connection between the wire end and the crimp terminal is provided by stripping the insulating coating layer at a wire end to expose the core wire, and swaging and crimping a core wire barrel of the crimp terminal to the exposed portion of the core wire. The connecting portion between the crimp terminal and the wire end is sealed with resin so as to prevent corrosion of the core wire due to ingress of moisture into the wire from the connecting portion (see Japanese Laid-Open Patent Publication No. 2001-167821 and Japanese Laid-Open Patent Publication No. 2012-069449, for example).
Further, this type of crimp terminal is manufactured by, for example, performing press molding such as punching and bending using a pressing device on a copper strip that is supplied by a conveyance device from a condition of being wound up into a roll shape. During the press molding, a chain-form chained terminal connected by carriers that are held by a conveyance mechanism is formed in order to convey the copper strip through the device. The chained terminal is then wound up into a roll shape again, whereupon the connection portion between the crimp terminal formed in a terminal shape and the electric wire terminal is typically sealed by resin in a resin sealing device.
However, the resin seal formed in the connection portion between the crimp terminal and the electric wire terminal gives rise to an increase in the manufacturing cost of the wire harness. This is because, in addition to the fact that the resin used is expensive in itself, time is required to apply and cure the resin in a resin molding process or a coating process.
Therefore, attempts have been made to obtain a sealed structure for the wire connection portion (the crimp portion) of the crimp terminal with by bending the wire connection portion into a tubular shape by press molding, and joining an entire butted interface between respective plate material ends, which is formed at the tubular shaped bent part by laser welding.
Meanwhile, during the process for manufacturing the crimp terminal, the press-molded chained terminal needs to be wound up and then transported to the subsequent laser welding process. The winding operation causes an increase in a number of operation processes, and moreover, causes deformation of the terminal while being wound up and the terminal becomes no longer horizontal or vertical relative to the carrier, and thus affects the quality of the laser welding performed in the subsequent process.
The present disclosure is firstly related to providing a terminal manufacturing apparatus in which a press-molded chained terminal can be conveyed to a subsequent laser welding process without being wound up, leading to improvements in welding quality and manufacturing speed.
The present disclosure is secondly related to providing a welding apparatus having a conveying/positioning mechanism that is capable of conveying a chained terminal that is being supplied after the press molding to a subsequent laser welding process without winding it up such that the laser welding can be performed while ensuring a conveyance speed and a positioning precision.
The present disclosure is thirdly related to provide a terminal manufacturing apparatus in which a press-molded workpiece is conveyed to a subsequent laser welding process so as to achieve improvements in welding quality and manufacturing speed.